An air strike on a market on Thursday killed at least 21 people, including three children, in a village of the north Syrian province of Aleppo, a monitoring group said.
The deadly raid comes amid a massive aerial offensive targeting opposition-held areas across Aleppo city and province that began in December 15, Naharnet reported.
The Syrian Observatory for Human Rights said the bombing campaign has killed hundreds, mostly civilians, and forced thousands of families to flee their homes.
"The number of people killed in an air strike this morning against the market area of Atareb village has risen to 21, including three children," said the Observatory, adding the toll was likely to rise.
Activists distributed video showing scenes of chaos, with bodies lying amid mounds of grey rubble in what was clearly a market.
The amateur footage shows a woman in a white headscarf screaming as she leaned over the body of a loved one.
Another image showed a man attending to a boy whose leg had been ripped off. It was unclear whether the child was alive or dead.
"The area that was struck today is a market area, that's why there were so many civilians killed," said Aleppo-based activist Abu Omar.
"The regime is hitting back against the civilians who support the revolt" against President Bashar Assad, he added.
Swathes of Aleppo city and province have been out of army control since 2012.
Human Rights Watch has accused Syria's regime of "wreaking disaster" with its air strikes on the area.
More than 150,000 people have been killed in Syria's three-year war, which broke out after the regime unleashed a massive crackdown against a protest movement demanding political change.
The violence has forced nearly half of Syria's population to flee their homes.